In the magnetic recording field, there has been a continuing development effort toward producing magnetic transducer heads of higher and higher resolution. As the transducing gap of the head is reduced in thickness, with a consequent reduction in gap reluctance, higher input signals to the head are generally required to produce a given level of recorded magnetization. The requirement for the use of a superimposed high frequency bias signal can result in undue heating of the head, particularly as the coercivity of the record medium is increased for the sake of higher resolution. The undue heating of the transducer head is undesirable not only because of possible damage to the record medium, but also because the record medium coating material may be softened and accumulate on the transducer head if the transducer head is operated at relatively high temperatures and slow speeds. Also the magnetic properties of the head core and of the record medium may be adversely affected.
While magnetic records can be monitored shortly after being made, such monitoring has typically been for the purpose of verifying the fact of a recording being made without the availability of immediate correction of the record in the event of an inaccuracy in the recorded signal.